drivers/dma/dw/rzn1-dmamux.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2022 Schneider-Electric
   4  * Author: Miquel Raynal <[email protected]
   5  * Based on TI crossbar driver written by Peter Ujfalusi <[email protected]>
   6  */
   7 #include <linux/bitops.h>
   8 #include <linux/of_device.h>
   9 #include <linux/of_dma.h>
  10 #include <linux/slab.h>
  11 #include <linux/soc/renesas/r9a06g032-sysctrl.h>
  12 #include <linux/types.h>
  13
  14 #define RNZ1_DMAMUX_NCELLS 6
  15 #define RZN1_DMAMUX_MAX_LINES 64
  16 #define RZN1_DMAMUX_LINES_PER_CTLR 16
  17
  18 struct rzn1_dmamux_data {
  19         struct dma_router dmarouter;
  20         DECLARE_BITMAP(used_chans, 2 * RZN1_DMAMUX_LINES_PER_CTLR);
  21 };
  22
  23 struct rzn1_dmamux_map {
  24         unsigned int req_idx;
  25 };
  26
  27 static void rzn1_dmamux_free(struct device *dev, void *route_data)
  28 {
  29         struct rzn1_dmamux_data *dmamux = dev_get_drvdata(dev);
  30         struct rzn1_dmamux_map *map = route_data;
  31
  32         dev_dbg(dev, "Unmapping DMAMUX request %u\n", map->req_idx);
  33
  34         clear_bit(map->req_idx, dmamux->used_chans);
  35
  36         kfree(map);
  37 }
  38
  39 static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
  40                                         struct of_dma *ofdma)
  41 {
  42         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  43         struct rzn1_dmamux_data *dmamux = platform_get_drvdata(pdev);
  44         struct rzn1_dmamux_map *map;
  45         unsigned int dmac_idx, chan, val;
  46         u32 mask;
  47         int ret;
  48
  49         if (dma_spec->args_count != RNZ1_DMAMUX_NCELLS)
  50                 return ERR_PTR(-EINVAL);
  51
  52         map = kzalloc(sizeof(*map), GFP_KERNEL);
  53         if (!map)
  54                 return ERR_PTR(-ENOMEM);
  55
  56         chan = dma_spec->args[0];
  57         map->req_idx = dma_spec->args[4];
  58         val = dma_spec->args[5];
  59         dma_spec->args_count -= 2;
  60
  61         if (chan >= RZN1_DMAMUX_LINES_PER_CTLR) {
  62                 dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
  63                 ret = -EINVAL;
  64                 goto free_map;
  65         }
  66
  67         if (map->req_idx >= RZN1_DMAMUX_MAX_LINES ||
  68             (map->req_idx % RZN1_DMAMUX_LINES_PER_CTLR) != chan) {
  69                 dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
  70                 ret = -EINVAL;
  71                 goto free_map;
  72         }
  73
  74         dmac_idx = map->req_idx >= RZN1_DMAMUX_LINES_PER_CTLR ? 1 : 0;
  75         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", dmac_idx);
  76         if (!dma_spec->np) {
  77                 dev_err(&pdev->dev, "Can't get DMA master\n");
  78                 ret = -EINVAL;
  79                 goto free_map;
  80         }
  81
  82         dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
  83                 map->req_idx, dmac_idx, chan);
  84
  85         if (test_and_set_bit(map->req_idx, dmamux->used_chans)) {
  86                 ret = -EBUSY;
  87                 goto free_map;
  88         }
  89
  90         mask = BIT(map->req_idx);
  91         ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
  92         if (ret)
  93                 goto clear_bitmap;
  94
  95         return map;
  96
  97 clear_bitmap:
  98         clear_bit(map->req_idx, dmamux->used_chans);
  99 free_map:
 100         kfree(map);
 101
 102         return ERR_PTR(ret);
 103 }
 104
 105 #ifdef CONFIG_OF
 106 static const struct of_device_id rzn1_dmac_match[] = {
 107         { .compatible = "renesas,rzn1-dma" },
 108         {}
 109 };
 110 #endif
 111
 112 static int rzn1_dmamux_probe(struct platform_device *pdev)
 113 {
 114         struct device_node *mux_node = pdev->dev.of_node;
 115         const struct of_device_id *match;
 116         struct device_node *dmac_node;
 117         struct rzn1_dmamux_data *dmamux;
 118
 119         dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
 120         if (!dmamux)
 121                 return -ENOMEM;
 122
 123         dmac_node = of_parse_phandle(mux_node, "dma-masters", 0);
 124         if (!dmac_node)
 125                 return dev_err_probe(&pdev->dev, -ENODEV, "Can't get DMA master node\n");
 126
 127         match = of_match_node(rzn1_dmac_match, dmac_node);
 128         of_node_put(dmac_node);
 129         if (!match)
 130                 return dev_err_probe(&pdev->dev, -EINVAL, "DMA master is not supported\n");
 131
 132         dmamux->dmarouter.dev = &pdev->dev;
 133         dmamux->dmarouter.route_free = rzn1_dmamux_free;
 134
 135         platform_set_drvdata(pdev, dmamux);
 136
 137         return of_dma_router_register(mux_node, rzn1_dmamux_route_allocate,
 138                                       &dmamux->dmarouter);
 139 }
 140
 141 static const struct of_device_id rzn1_dmamux_match[] = {
 142         { .compatible = "renesas,rzn1-dmamux" },
 143         {}
 144 };
 145 MODULE_DEVICE_TABLE(of, rzn1_dmamux_match);
 146
 147 static struct platform_driver rzn1_dmamux_driver = {
 148         .driver = {
 149                 .name = "renesas,rzn1-dmamux",
 150                 .of_match_table = rzn1_dmamux_match,
 151         },
 152         .probe  = rzn1_dmamux_probe,
 153 };
 154 module_platform_driver(rzn1_dmamux_driver);
 155
 156 MODULE_LICENSE("GPL");
 157 MODULE_AUTHOR("Miquel Raynal <[email protected]");
 158 MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");